1. Field of the Invention
This invention relates to an improved process for the production of 17-hydroxyandrosta-1,4-dien-3-one and androsta-1,4-diene-3,17-dione by the microbiological oxidation of a sterol, its 4-en-3-one derivative or its 1,4-dien-3-one derivative.
2. Description of the Prior Art
17-Hydroxyandrosta-1,4-diene-3-one and androsta-1,4-diene-3,17-dione are commercially significant intermediates for the synthesis of valuable steroidal hormones. It has long been known that 17-hydroxyandrosta-1,4-dien-3-one (1-dehydrotestosterone) (hereinafter referred to as DHT) and androsta-1,4-diene-3,17-dione (hereinafter referred to as ADD) are formed by the microbiological oxidation of sterols. However, this process suffers from the disadvantage that the formed DHT and ADD are subject to further oxidation which results in poor yields of DHT and ADD. U.S. Pat. No. 3,388,042 to Arima et al., issued June 11, 1968, discloses the microbiological oxidation of sterols to ADD through the use of a chelating agent capable of forming chelate compounds with iron and copper ions which are present in the culture medium and which participate in the microbiological oxidation of ADD. Although this process permits the avoidance of the further oxidation of ADD to give excellent results, it has not achieved commercially attractive yields and conversions. Therefore, improvement in the process was required to improve such yields and conversions.
It is well known that media containing fats and oils are employed in the microbiological oxidation of steroids. U.S. Pat. No. 2,756,179 to Josef Fried et al., issued July 24, 1956, describes in Example 1 the use of a medium containing about 0.22 percent by weight of soybean oil and about 1.5 percent by weight of soybean meal in the microbiological oxidation of progesterone to ADD and DHT. U.S. Pat. No. 2,842,566 to Jean P. Rosselet et al., issued July 8, 1958, describes in Example 1 the use of a medium containing about 0.1 percent by weight of lard oil in the microbiological oxidation of 6.alpha.-methyl-11-ketoprogesterone to 1-dehydro-6.alpha. -methyladrenosterone and 1-dehydro-6.alpha. -methyl-11-ketotestosterone. U.S. Pat. No. 2,981,659 to Gunther S. Fonken et al., issued Apr. 25, 1961, describes in Example 4A the use of a medium containing about 1.5 percent by weight of soybean meal and about 0.25 percent by weight of soybean oil in the microbiological oxidation of progesterone 20-ethylene ketal to 1-dehydroprogesterone 20-ethylene ketal. It also describes in Example 5A the use of a medium containing about 0.22 percent by weight of soybean oil or about 0.2 percent by weight of lard oil in the microbiological oxidation of progesterone 20-ethylene ketal to 1-dehydroprogesterone 20-ethylene ketal. U.S. Pat. No. 3,010,876 to Dan J. Badia et al., issued Nov. 28, 1961, describes in Example III the use of a medium containing about 0.27 percent by weight (10 ml./gal.) of soybean oil in the microbiological oxidation of Compound S to Compound F. U.S. Pat. No. 3,047,469 to Charles John Sih et al., issued July 31, 1962 discloses the use of a medium containing about 0.22 percent by weight of soybean oil in dehydrogenating the A ring of steroids having A rings which are fully or partially saturated in that ring. U.S. Pat. No. 3,536,586 to Bong Kuk Lee et al., issued Oct. 27, 1970, discloses the use of a medium containing about 0.22 percent by weight of soybean oil and about 1.5 to 2.0 percent by weight of soybean meal in 1-dehydrogenating and 16-hydroxylating a steroid which is saturated in the 1,2-position and which has a replaceable hydrogen atom in the 16-position. Japanese Patent published 16147/1971 describes in Example 4 the use of a medium containing about 0.1 percent by weight of soybean oil in the microbiological oxidation of cholesterol to ADD and androst-4ene- 3,17-dione. Japanese Patent published 29193/1971 describes in Example 1 the use of a medium containing 0.2 percent by weight of soybean oil in the microbiological oxidation of lithocholic acid to ADD and androst-4-ene-3,17-dione. Biotechnology and Bioengineering 11 1255-1270 (1969) discloses the use of a medium containing about 0.22 percent by weight of soybean oil and about 1.5 to 2.0 percent by weight of soybean oil meal in the microbiological oxidation of 9.alpha.-fluoro-11.beta.,17,21-trihydroxy-pregn-4-ene-3,20-dione-21-acetat e to 9.alpha.-fluoro-11.beta.,16.alpha.,17,21-tetrahydroxy-pregna-1,4-diene-3,2 0-dione.
However, the addition of such a small amount of the fat to the culture medium in the microbiological oxidation of sterols results in a slight increase in the yields of DHT and ADD.